Performance And Emissions Modeling Of Natural Gas Dual Fuelling Of Large Diesel Engines

摘要

ABSTRACT: This paper presents numerical investigations the combustion characteristics and maximum possible natural gas substitution on a large stationary diesel engine dual fuelled with natural gas operation at 600 RPM. The performance effect in the dual fuel diesel engines is investigated using the coupled 1D/3D computer simulation of GT-POWER and KIVA-3 computer codes for combustion optimization and emissions reduction. Numerical modeling was performed by varying engine load conditions from 100% to 77%, while with increasing the quantity of natural gas substitution from up to 80%. The main target of this contribution is to examine the combustion characteristic of a heavy duty 18 cylinder, 6 MW electricity generator diesel engine operating in dual fuel mode at various engine loads. Results indicate that up to 80% natural gas substitution is possible over wide range of engine load conditions at higher engine loads. However, for 77% engine load conditions depict noticeable engine performance deterioration above 60% natural gas deterioration, of particular, is higher BSFC and excessive CO emissions. Compared with straight diesel, the in-cylinder NOx formation was significantly reduced by as the quantity of natural gas substitution was increased. For example, NOx was reduced by 50% while engine at 80% engine load fuelled with 60% natural gas substitution. This is consistent with the reduced peak flame temperature observed in the combustion chamber, and that was confined with the fuel spray zone.